The present invention relates to a new 5xe2x80x2 regulatory sequence allowing the expression, in monocotyledonous plants, of a sequence heterologous to the said regulatory sequence, encoding a protein of interest. The present invention also relates to a chimeric gene comprising the said regulatory sequence, a heterologous sequence encoding a protein of interest and a 3xe2x80x2 regulatory sequence allowing the expression of the protein of interest in a plant cell from a monocotyledonous plant, as well as a transformed monocotyledonous plant comprising the said chimeric gene and the means necessary for the transformation of plant cells and of plants.
Various promoters allowing the expression of sequences encoding proteins of interest in plants are known, are described in the literature, and have already allowed the development, to a commercial stage, of plants modified by genetic engineering. They are promoter sequences of genes which are expressed naturally in plants, in particular promoters of bacterial, viral or plant origin such as, for example, that of a gene for the ribulose bisphosphate carboxylase/oxygenase small subunit (U.S. Pat. No. 4,962,028) or of a gene of a plant virus such as, for example, that of cauliflower mosaic (U.S. Pat. No. 5,352,605). Promoters allowing the expression of heterologous genes in plants are in particular described in the following patents and patent applications: U.S. Pat. No. 5,086,169, EP 0 353 908, U.S. Pat. Nos. 5,139,954, 5,378,619, 5,563,328, 5,589,583, 5,633,363, 5,633,439, 5,633,440, 5,633,447, 5,635,618, 5,639,948 and 5,639,952.
However, some of these promoters, and more particularly the promoters of plant origin, are not functional in monocotyledonous plants.
Arabidopsis sp. histone promoters described in patent application EP 0,507,698 are for example known which are particularly efficient for allowing the expression of a heterologous gene in dicotyledonous plants such as tobacco, oil seed rape or soya bean, which are not functional in monocotyledonous plants such as maize.
The rice actin promoter is a promoter known to allow the expression of heterologous genes in monocotyledonous plants (U.S. Pat. No. 5,641,876). However, the problem of identifying new functional 5xe2x80x2 regulatory sequences for the expression of heterologous sequences in monocotyledonous plants still remains.
The present invention relates to a new DNA sequence, a 5xe2x80x2 regulatory element allowing the expression of a heterologous gene in a plant cell from a monocotyledonous plant, the said DNA sequence comprising, in the direction of transcription, a first DNA sequence, which is a functional fragment of the sequence of the maize H3C4 promoter, and a second DNA sequence, which is a functional fragment of the sequence of the first intron of rice actin.